If you think everything is going to Hades in a handbasket, just remember that things always could be worse. Personally, we always find that it lifts our spirits to re-watch some 1960s-1970s dystopian apocalyptic thriller, preferably one starring Charles “Take your stinking paws off me, you damn dirty ape!” Heston, such as “Planet of the Apes,” “The Omega Man,” or “Soylent Green,” in which the Chaz-man discovers that the fast-food treat that the Earth’s burgeoning population is gobbling down contains, well…you’ll have to see the movie. But in the meantime, we’ve got some shows this weekend that will help you shed that gloomy outlook and gain some perspective.

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ust be glad, for example, that you’re not a denizen of some vanished culture. On Friday at 7p et/pt, tune in for “Explorer: Lost Cities of the Amazon,”a look at recently-discovered scientific evidence that legendary civilizations in the jungle actually existed.Then, on Saturday at 10p et/pt, tune in for “Explorer: American Doomsday,“ a look at how national security planners contemplate seemingly unthinkable catastrophes, in an effort to make sure that we don’t become one of those vanished civilizations. Oh, and here also are the science and technology headlines.Okay, now for the news.